Transmitting apparatus for wireless telegraph and telephone systems.



F. G. SIMPSON.

TRANSMITTING APPARATUS FOR WIRELESS TELEGRAPH AND TELEPHONE SYSTEMS. APPLICATION FILED NOV. I6. I915 1 03,064. Patented Oct. 31, 1916.

WITNESS IN VE N TOR n/.1 l1 TTOBNEY UNITED STATES PATENT OFFICE.

FREDERICK G. SIMPSON, OI SEATTLE, WASHINGTON.

TRANSMITTING APPARATUS FOR WIRELESS TELEGRAPH AND TELEPHONE. SYSTEMS.

To all whom it may concern:

Be it known that -I, FREDERICK G. SIMP- soN, citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented a certain new and useful Improvement in Transmitting Apparatus for Wireless Telegraph and Telephone, Systems, of which the following is a specification. V

My invention relates to improvements in transmitting apparatus of wireless telegraph and telephone stations and the object of my improvements is to provide electrical apparatus, including an antenna, electric circuits and an electric generator for supplying a direct current of electricity, which shall be adapted to propagate and control electrical impulses having the form of slightly damped oscillations that are normally of a constant frequency, which oscillations may be varied in amplitude and persistency, as required, to cause distinctive electromagnetic wave trains representing intelligible messages to be radiated from said antenna to actuate suitable translating devices of a distant station; and a further object of my improvementsis to arrange such apparatus so that distinctivevariations in the electrical condition of said circuits, as efi'ected by the impulse-controlling member, shall produce corresponding variations tha are. more nearly of the same degree in t e electrical condition of the antenna than has been possible in the operation of transmitting apparatus heretofore employed in wireless telegraph and telephone systems. I accomplish these objects by devices illustrated in the accompanying drawing wherein- 1 designates a direct current electric gen erator provided with a positive terminal 2 and a negative terminal 3, said positive terminal 2 being connected by a conductor 4 with one terminal 5 of a current controlling device 6 (.as a telegraph key or a telephone transmitter) whose other terminal 7 is connected by a conductor 8 with the anode 9 of a mercury valve 10, of well known form; the cathode 11 of said mercury valve 10 being connected by a conductor 12 with one terminal of a resistance'coil 13 whose other terminal is connected by a wire 14 with the earth 15.,

The mercury valve 10 is provided with an auxiliary anode 16 to which is connected Specification of Letters Patent.

Application filed November 16, 1915.

Patented Oct. 31, 1916.

Serial 1*). 61,844.

by a conductor 17 one terminal of a switch 18 whose other terminal is connected with the positive terminal of a source of electricity, as a battery 19, whose negative terminal isconnected to the conductor 12 thereby constituting a local circuit between the cathode 11' and the auxiliary anode 16, which local circuit includes the conductor 17, switch 18, battery 19 and a portion of the conductor 12.

The negative terminal 3 of the electric generator 1 is connected by a conductor 20 to one end of both of two conductors 21 and 22, the other end of conductor 21 being connected to one side 23 of a variable condenser 24 whose other side 25 is connected by a conductor 26 to the conductor 14 at.a point thereon between the resistance coil 13 and the earth 15, while the other end of the conductor. 22 is connected to the outer terminal of a spiral 27 whose inner terminal is connected to one terminal of a variable inductance 28 whose other terminal is connected to an antenna 29.

An adjustable spark-gap 30 is disposed with one of its terminals connected to a point 31 on the outermost convolution of the spiral 27, while its other terminal is connected to the conductor 26 at a point between the conductor 14 and the side 25 of the variable condenser 24.

The operation-of the apparatus when arranged as illustrated and described is as follows: First, the switch 18is closed andthen the mercury valve 10 is tilted sidewise in a direction to cause its mercury (indicated by broken lines 32) to flow toward, and make connection with, the auxiliary anode 16 thus completing a circuit through the conductor 17, switch 18, battery 19, a portion of the conductor 12, the cathode 11v and the mercury within the bottom portion of the mercury valve 10, through which circuit current'of the battery 19 may flow, and thereupon the mercury valve 10 is moved back to its perpendicular position thereby to cause the current from'the battery 19 to form an electric arc between the auxiliary anode 16 and the mercury 32thus generating mercury vapor within the mercury valve 10, in a manner well known, which mercury vapor may serve as a conductor through which current may pass between the anode 9 and the mercury 32, The mercury valve 10 having been thus primed, an actuation of the current controlling device 6, (which may be a telegraph key or a telephone transmitter) will cause variations in the flow of current from the positive terminal 2 of the direct current generator 1 through the conductors 4 and 8, the mercury valve 10, conductor 12, and resistance coil 13'to the conductor 14 and therefrom to both the earth 15 and through the conductor 26 to side 25 of the condenser 24, thereby charging the earth 15 (as one side of a condenser whose other side is the antenna 29) and the side 25 of the condenser 24.

Preferably, the spark-gap 30 is adjusted to break down by a voltage equal to, or slightly greater than, the difference in potential between the terminals of the generator 1, such adjustment being practicable owing to the effect of inductance distributed throughout the charging circuit.

The time required to charge the condenser 24 toa voltage. suflicient to break down the spark-gap 30, with which it is connected as shown, depends upon its capacity and the amount of resistance and inductance of the charging circuit, and when it becomes charged to such degree as will break down spark-gap 30 then it will discharge in the direction from side 25 through spark-gap 30, thence through outer convolution of spiral 27 from point 31 to conductor 22 thence through conductor 21 to side 23 of said condenser 24 and such discharge will be simply a single impulse that again will charge the condenser-24 in a direction that will reverse its polarity.

In the circuit comprising the variable condenser 24 the spark-gap 30, a portion of the outer convolutions of the spiral 27 and the conductors 22 and 21, the amount of capacity in proportion to the amount of inductance is extremely large, the resistanceof such circuit being largely situated in the spark-gap 30.

It is a well known fact that in circuits where the ratio of capacity to inductance is large, and where a condenser is permitted to discharge through a spark-gap the tendency of such discharge is to create oscillations which atfirst are relatively of high amplitudebut which rapidly decrease in amplitude and are therefore few in number, and thus in the circuit comprising the condenser 24 the spark-gap 30, a portion of the outer convolution of the spiral 27 and the conductors 22 and 21 therewill be no flow of current in a direction that is the reverse of the said discharge of the condenser 24, which fact is also due to the fact that the circuit through condenser 24, conductors 21 and 22, the whole of spiral 27, the variable inductance 28, antenna 29, earth 15, a portion of conductor 14 and the conductor 26 constitutes a circuit wherein oscillations may have great persistency, and contemplating the condenser 24 together with the antenna 29 and the ground 15 as two condensers in series, the second half of any oscillation start ing from condenser 24 is directed through the circuit consisting of said condenser 24, conductors 21 and 22, the whole of spiral 27 inductance 28, antenna 29, earth 15, a portion of conductor 14 and the conductor 26, and all subsequent oscillations will persist within that circuit and will not pass across spark-gap 30, provided said spark-gap '30 is adjusted as hereinbefore described, and further provided that there is no arc existing between the electrodes of said spark-gap 30, which are may not exist by reason of the action of the mercury valve 10 because at the moment of the initial discharge of the condenser 24 the current through said mercury valve 10 is zero and therefore the voltage derived therefrom between the electrodes of the spark-gap 30 is zero.

The mercury valve 10 also prevents the variable condenser 24 from discharging any of its energy back through the direct current generator 1.

A waste of energy of the initial discharge of the condenser 24 is prevented by the inductive relation between that portion of the outermost convolutions of the spiral 27 and the remaining convolutions of said spiral 27,. said portions of such outermost convolution forming a part of the circuit which includes the conductors 22. and 21 together with the condenser 24 and spark-gap 30 (which circuit I call the discharge circuit or trigger circuit) while the remaining convolutions form a part of a circuit which I .call the oscillating circuit' and whichincludes the whole of the spiral 27, the inductance 28, antenna 29, ground 15, portion of the conductor 14, the conductor 26, the condenser 24 and the conductors 21 and 22. Such inductive relation between said trigger circuit and said oscillating circuit is not absolutely necessary, but it improves the efficiency of the apparatus. After a period of time (de pendent upon the capacity of the condenser 24, the amount of resistance of the coil 28, the amount of resistance of the mercury valve 10 and the amount of other resistances in the charging circuit. together with the inductancedistributed throughout said charging circuit including the inductances of the generator 1 and the mercury valve 10) the condenser 24 is charged anew and then the same cvcle of operations is repeated.

Intelligible signals may be formed in the usual way by the manipulation of a telegraph key acting as a current controlling device 6, which signals will be emitted in the usual manner from the antenna 29 in the form of groups of electromagnetic wave trains. These groups, however, are so closely associated one with another that a receiver similar to the heterodyne or tikker type will best serve to distinguish them at a distant receiving station.

What I claim is:

1. In wireless telegraph and telephone systems, the combination with a charging circuit, which includes as parts of it a. source of a direct current of electricity, a current-controlling device, a rectifying valve, a resistance coil and a condenser; of a trigger circuit, which includes aportion of a spiral conductor, a spark-gap and a part of said charging circuit within which is included said condenser; and an oscillating circuit, which includes all of said spiral conductor, a variable inductance, an antenna, an earth connection and that part of each of said charging and trigger circuits which includes said condenser.

In ,wi'reless telegraph and telephone systems, the combination with a charging circuit, of a trigger circuit and an oscillating circuit; said charging circuit including a source of a direct current of electricity, a

current-controlling device, a mercury valve, a resistance coil and a condenser; said trigger circuit including a spark-gap, a portion of a spiral conductor and that part of said charging circuit within which is disposed said condenser: while said oscillating circuit includes all of said spiral coil, a variable inductance, an antenna, an earth connection and that part of each of said charging and trigger circuits which includes said condenser.

3.. Transmitting apparatus for wireless telegraph and telephone systems, which embodies a charging circuit, a trigger circuit, and an oscillating circuit which includesan antennain metallic connection therewith; a

rectifying valve disposed in said chargingcircuit; and a-spirally wound conductor, one portion of whose length is included in saidtrigger circuit while the whole of its length is included in said oscillating circuit, whereby said trigger circuit and said oscillating circuit may be inductively related to each other in addition to being in metallic connection with each other.

1. Transmitting apparatus for wireless telephone systems, which embodies a charging circuit; means for supplying said charg ing circuit with a direct current of electricity; means for varying the resistance of said charging circuit in response to air vib 'ations; a rectifier connected in said charging circuit; a condenser connected in said charging circuit; a trigger circuit which includes that portion of said charging circuit within which is disposed said condenser: a spark-gap connected in said trigger circuit; a spiral conductor one portion of which is connected in said'trigger circuit; an oscillating circuit in which is connected the entire length of said spiral conductor and in which is connected that portion of said charging circuit containing said condenser and within which is connected a variable inductance and an antenna. said oscillating circuit being also connected with the earth.

5. Transmitting apparatus for wireless telegraph systems, which embodies a charging circuit; means for charging circuit with a-dircct current of electricity; a telegraph hey connected in said charging circuit: a rectifier connected in said charging circuit; a condenser connected in said charging circuit: a trigger circuit which includes that portion of said charging circuit within which is disposed said condenser; a spark-gap connected in said trigger circuit; a spiral conductor one portion of which is connected in said trigger circuit: 'an oscillating circuit in which is coni'iected the entire length of said spiral conductor and in which is connected that portion of said charging circuit containing said condenser and within which is connected a variable inductance and an antenna, said oscillating circuit being also connected with the earth.

In witness whereof. I hereunto subscribe my name this fourth day of November,

FREDERICK (i. SIMPSON. Witnesses 1 FRANK IVARREX. O. Jorn'sox.

supplying said 

